Polymer dispersion-type liquid crystal optical device and method for producing the same

A liquid crystal optical device including: a liquid crystal/polymer composite film including matrix polymer composed mainly of a transparent resin having an ionic dissociative group and, dispersed therein, a liquid crystal particle; and conductive substrates sandwiching the liquid crystal/polymer composite film therebetween, at least one of the conductive substrates being transparent. A method for producing the liquid crystal optical device according to the present invention includes the steps of dispersing a liquid crystal in a dispersion medium composed mainly of water to prepare an oil-in-water type emulsion; preparing a composition for electrodeposition through the use of the resultant emulsion and a resin for a matrix polymer; electrodepositing the composition for electrodeposition on a conductive base material to form an electrodeposited coating; and drying the electrodeposited coating to form on the conductive base material a liquid crystal/polymer composite film including a matrix polymer and, dispersed therein, a liquid crystal particle.

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Claims

1. A liquid crystal optical device comprising:

a liquid crystal/polymer composite film comprising a matrix polymer comprising a transparent ion dissociative acrylic or vinyl copolymer resin having an acid value of 20 to 200, said resin containing at least one group capable of dissociating to an anionic group;
a liquid crystal particle dispersed in said resin; and
conductive substrates sandwiching the liquid crystal/polymer composite film therebetween, at least one of said conductive substrates being transparent.

2. A liquid crystal optical device according to claim 1, further comprising a patterned resist for sealing said liquid crystal/polymer composite film.

3. A liquid crystal optical device according to claim 1, wherein said liquid crystal particle is encapsulated in a transparent polymer having a refractive index similar to that if said matrix polymer, said transparent polymer and said matrix polymer each having a refractive index in the range of about 1.3 to about 1.7.

4. A liquid crystal optical device according to claim 2, wherein said liquid crystal particle is encapsulated in a transparent polymer having a refractive index similar to that of said matrix polymer, said transparent polymer and said matrix polymer each having a refractive index in the range of about 1.3 to about 1.7.

5. A liquid crystal optical device according to claim 1, wherein said anionic group comprises a carboxyl group, a phospate group or a sulfonate group.

6. A liquid crystal optical device according to claim 1, wherein said matrix polymer has a glass transition point of 0.degree. to 100.degree. C. and a number average molecular weight in the range of from 10,000 to 200,000.

7. A liquid crystal optical device according to claim 2, wherein said matrix polymer is a copolymer of at least one monomer represented by the formula CH.sub.2.dbd.C(R.sub.1)--R.sub.2 --COOH wherein R.sub.1 represents hydrogen or a methyl group and R.sub.2 represents a hydrocarbon compound, having 2 to 10 carbon atoms, which may be absent with at least one monomer represented by the formula CH.sub.2.dbd.C(R.sub.1)--COOR.sub.2 wherein R.sub.1 represents hydrogen or a methyl group and R.sub.2 represents a hydrocarbon compound, having 1 to 10 carbon atoms.

8. A liquid crystal optical device according to claim 1, wherein said liquid crystal/polymer composite film before sandwiching between the conductive substrates has a thickness of 3 to 15.mu.m and a surface roughness of 1.mu.m or less.

9. A liquid crystal optical device according to claim 2, wherein said liquid crystal/polymer composite film before sandwiching between the conductive substrates has a thickness of 3 to 15.mu.m and a surface roughness of 1.mu.m or less.

10. A liquid crystal optical device according to claim 1, wherein the average particle diameter of the liquid crystal particle is 1 to 5.mu.m.

11. A liquid crystal optical device according to claim 2, wherein the average particle diameter of the liquid crystal particle is 1 to 5.mu.m.

12. A liquid crystal optical device according to claim 1, wherein a dye is contained in the matrix polymer.

13. A liquid crystal optical device according to claim 1, wherein said liquid crystal particle comprises a dichroic dye.

14. A liquid crystal optical device according to claim 13, further comprising regions capable of exhibiting hues of three primary colors of R, G and B.

15. A liquid crystal optical device according to claim 14, wherein a black matrix is provided in a space between picture elements of R, G and B.

16. A liquid crystal optical device according to claim 15, wherein said black matrix comprises a resist to which a black color has been given.

Referenced Cited
U.S. Patent Documents
5085973 February 4, 1992 Shimizu et al.
5095379 March 10, 1992 Fukunaga et al.
5274481 December 28, 1993 Kim
5427713 June 27, 1995 Wartenberg et al.
5484552 January 16, 1996 Wartenberg et al.
5496497 March 5, 1996 Takiguchi et al.
5498450 March 12, 1996 Akashi et al.
5516455 May 14, 1996 Jacobine et al.
Patent History
Patent number: 5843332
Type: Grant
Filed: Nov 15, 1994
Date of Patent: Dec 1, 1998
Assignee: Dai Nippon Printing Co., Ltd.
Inventors: Satoshi Takeuchi (Tokyo), Masayuki Ando (Tokyo), Tatsuya Tabei (Tokyo), Tadafumi Shindo (Tokyo), Hiroki Maeda (Tokyo), Hideshi Hattori (Tokyo), Kei Ikegami (Tokyo)
Primary Examiner: C. H. Kelly
Law Firm: Parkhurst & Wendel, L.L.P.
Application Number: 8/339,748
Classifications
Current U.S. Class: 252/29901; Polymer Liquid Crystal (349/183)
International Classification: C09K 1952; G02F 113;